An optical transceiver generally installs a transmitter optical module to convert an electrical signal to an outgoing optical signal output from a transmitter optical receptacle as an outgoing signal, and a receiver optical module to convert an incoming optical signal provided from a receiver optical receptacle to an electrical signal. One type of optical transceivers has a feature that the transmitter optical module and the receiver optical module implement the transmitter optical receptacle and the receiver optical receptacle, respectively. A Japanese Patent application laid open No. 2006-086433A has disclosed such an optical transceiver.
However, recent optical transceivers enhance the function implemented therein, which resultantly enlarges the size of the transmitter and receiver optical modules. Enlarged modules inevitably narrow a space between the modules, and a span between two fibers sometimes exceeds a standard for the two-wired optical connector. A U.S. Pat. No. 7,785,020, has proposed a technique to couple two modules with the optical connector by inner fibers.
Moreover, as the optical transceiver reduces the dimensions thereof, the inner fiber connecting the modules with the optical connector is required to satisfy the limitation of the fiber bent loss. An optical fiber is limited in the curvature thereof at a bent from the view point of the optical loss and the long term reliability.